Project summary The Icahn School of Medicine at Mt. Sinai is requesting funds for the purchase of a Helios Mass Cytometer, manufactured by Fluidigm Inc., to facilitate basic, translation and clinical research discovery. Mass cytometry is a cutting edge technology that merges the high-throughput single cell analysis of flow cytometry with the specificity and resolution of mass spectrometry; antibodies conjugated to purified rare-earth metal isotopes are used to label complex mixtures of cells, which are then analyzed by time-of-flight mass spectrometry. By overcoming the limitations of fluorescent spectral emission, this allows over forty parameters (with the potential for over 100 with future reagent development) to be simultaneously measured on a single cell basis, thereby allowing deeper phenotypic and functional profiling of heterogeneous cell samples to yield mechanistic insights into biological processes and novel biomarkers of disease progression and responses to therapy. While mass cytometry offers tremendous potential for scientific discovery, some of the major challenges in successfully establishing this technology include the need for specialized infrastructure, technical and scientific expertise, reagents and protocols, and computational resources. Mt. Sinai acquired a second-generation CyTOF2 mass cytometry in 2013 and has already successfully overcome all these challenges to establish a highly-productive full-service mass cytometry program as part of the Human Immune Monitoring Core, which is currently utilized by over 50 NIH-funded investigators. The impetus for this application is that our current instrumentation is utilized at capacity, and we require a second instrument to meet the growing mass cytometry needs of our scientific and clinical community. By having already heavily invested in the necessary infrastructure and reagents, and established deep scientific, technical, computational expertise related to mass cytometry, we can assure the smooth and successful integration of a Helios mass cytometer and maximize its impact on Mt. Sinai's translational and clinical research efforts.